Which bike for ORS?
Definately can't do level 2 without doing level 1, when you get there they ask who is a complete off road novice or not. go with the non novices, use an 800, not as tiring as the 12 and much better than the 6. Take a camelbak
I'm with BigBird on this the Level 1 starts with lots of skills practice, they soon sort out your abilty level and group accordingly so you don't loose time out to the complete beginners (like me). Day 1 PM i was put into a group that had previuos experience, this notched things up for me, so I was challenged but not over-whelmed. The instructors push you but do not over-whelm you. You sleep well afterwards.
As far as bike choice goes its a personnal preference thing, except the 800 does take a bit more ability, with the 1200 you can keep chugging on through so is probably the better first timers choice. Picking either up is much the same, the 1200 carries it's weight lower so effort is much the same (I've had some practice at this on both). Also, the instructors help whenever you are struggling and never make you feel like you are holding things up. {All the instructors are excellent and go out of their way to ensure you enjoy and get the best out of your days, they instruct for your benefit not theirs)
If you do not have a Camelbak it's not a problem as you can carrry water bottles on the bikes and there is plenty available at the rest points, along with fruit, energy bars and Ibuprofen ~ Beer of bike induced needs. I prefer this my camelbak always tastes of the chemical cleaners regardless of what I do to clean it.
I loved the Level 1, after years of pontificating about should I go, so much so I got home and booked Level 2 / Day in the Dirt / Brecon Beacons 2 day ride. I also bought a 250 dual purpose bike for larking about on in the mud, not planning to pick my 1200 up, that is the only issue with doing the ORS - you can get hooked and spend all your money ~ in a good sort of way.
And finally, Touratech are next door suggest you try to resist or the Credit Card can take a big hit.