Finally got around to fitting some Reba Team forks to an old bike. I did ride with them once before but they were never actually setup so they are almost as rigid as a rigid fork.

Any suggestions on pressures for a rider weighing approx 12st?

Also (and hence the reason they were never setup properly), I don't have a shock pump – any (cheap) recommendations?

You need sme way of putting in the region of 100 – 130lb. Hence the shock pump. A normal tyre pump won't do that.
Start at around 110lb in each chamber & work from there.

edit Oops, Reba's. My advice was for Revs (must read posts properly…). Don't know about Reba's.

Yeah, those pressures all seem reasonable (anywhere between 110 and 130).

Getting the pressure right in the positive chamber is fairly easy with a little trial and error. Because you have the negative chamber you can set the positive chamber soft enough that you get full travel regularly, so set the fork, ride one of your regular trails fairly hard and aim to achieve almost full travel (there will be a ring of muck/oil on the stanchion to show you this, or use a zip tie).

Once you can do that you can then fiddle with the negative chamber to adjust how much sag/bob you get. Lots of sag equals lots of grip (+ bob…) but the fork will sit low which can be a bit scary at high speeds or steep stuff.

I've now set mine up with about 130 in the positive chamber and 90 in the negative chamber. This is maybe a bit extreme but I use them for ragging about singletrack, so having them nice and stiff makes the bike a LOT more agile, I find myself popping and jumping a lot more. Once I hit something hard enough though the fork will open up and give me full travel (sort of like a platform on a rear shock).

If I were heading for the mountains where I was more worried about grip then I would maybe set them up with more sag.

The beauty of Rebas is that they're so customisable, so its worth messing about and experimenting, get a decent shock pump to make this easier and maybe carry it with you.

I weigh about the same as you and run 105+ve and 100-ve, with about 1/3 rebound. Like monk says it kind of depends what you're riding. I tried running them with more -ve like a lot of people recommend but found them too divey. What I've got now seems to be the best compromise between suppleness in the rooty sections and stiffness off the (smaller) drops on my local trails.