Wow. At least it sounds like there is 'buy in' to move forwards and upwards. That's good. Trying to be a 'change agent' is ... shall we say very difficult. Hopefully, 2 *will* cause faculty members/instructors to re-think and change what they are doing keeping in mind the student experience foremost in their minds. (bet there are more and more of your students using handheld device and smartphones than ever before now ... and that's something to keep in mind. When you finally arrive at your destination (Moodle 2.4.x/or 2.5 by then) ... it won't be Kansas anymore!
Amazing how long a 1.8.1 Moodle has survived usage/internet ... on Linux, isn't it? Hmmmm ... wonder if that's not something to be considered.
"don't honestly know anything concrete about it or Linux"
Moodle is 'typically' comprised of a bunch of PHP files/scripts which talk to MySQL DB on the backend and is served out by Apache. So how much experience does one have with PHP, MySQL, or Apache? (any platform)? Does running Windows really give one an advantage? Hint: easy installers are but the tip of the iceburg and last time I looked, MySQL and Apache are 'faceless' server apps. Those apps (should you resist a hybrid install of Moodle) are not native to Windows. No 'native to Windows' control panels, etc.. The 'burg' part ... updating the apps that run Moodle - MySQL, PHP, and Apache.
Guess you can tell what my preference is, can't ya? ;)
*IF* on tries the 'migration' route ... ie, move the 1.8->1.9->2.2->2.3->2.4 regardless of what you'd like to be upon, the first step will be on the LInux server using mysqldump and tar balling up the moodledata directory + getting the config.php file that resides in the moodle code directory. May also take stock of any add-ons the 1.8.1 might have and start researching just how mission critical those were to faculty. Some add-ons made the trip to 1.9 but haven't in 2.x. Having done that, one might discover Linux is not so bad! You then, can 'learn something new' right along the faculty members who will be re-learning the new Moodle.
The really fun part also related to the Moodle code. I know others will 'take pity' and say I'm wrong, but ... I'd start learning how to 'git' the Moodle code using 'git' (another app not native to Windows). I, personally, have taken a site from 1.6 -> 1.7 -> 1.8 -> 1.9 (and now to 2.x) and would have loved to be using git as opposed to cvs. Job would have taken a lot less time.
Basically, with a migration such as this one, it's one step at a time - check the upgrade to the next highest version, then backup all of what you've gained - the DB, the data directory, and the code directory (even though the code directory won't be used on the next step upwards cept for one file: config.php). That backup of an upgraded 1.8.x to it's highest becomes your 'fall back position' should more work need be done on the next step).
Along the way one would have to 'study up' on changes required ... DB needs to be character set utf8 and collation may as well be set to utf8_general_ci as soon as one can. That will be required when you hit version 2 so may as well do that early on.
If on a Linux server that doesn't need upgrading ... although I'll be if the version of Moodle is 1.8.1, the operating system itself is probably in dire need of updates ... in that first step, one has learned at least 40% of what's needed to move forward.
Ok, let's say you start fresh with a 2.4.x+ ... the highest available right now. Don't think that courses from 1.8.1 can be restored to a 2. 1.9 backups can (sometimes with some work).
OR, one could start fresh on new box (your choice of flavor) ... leave the old server up ... and let the faculty/teachers copy and paste from old to new. Hmmmm ... they'll 'enjoy' that! BUT, it will cause some online instructors to re-think/re-design their courses (although bet most won't). They will, however, have to download docs,pdfs, etc. they have in their courses to re-upload them in the new ... OR ... you could turn on file system repositories, get the course ID folders from the 1.8.1 then onto and into repostories on the 2 server and then as a faculty member starts the process, set their repository to be their old course ID folder ... they don't have to download just to upload again - files are already there. You would want to remove any backup zips and any moddata directories found in their couse ID folders ... useless stuff in 2.
My 2 cents!
'spirit of sharing', Ken