yeah man, probably lots of other folks here with more knowledge than me too..
I know that a few years ago I kind-of went through the same upgrade thing on my old bike. I bought a rock shocks reba, discs, a decent wheel set, nice shifters, ect.
after moving out here I realized that the bike really didn't fit me (frame too small) so i set out looking for a used bike I could afford. I ended up with my Spot for about $900. Honestly, it has all of the components i had ended up upgrading on my old frame... but it was a newer nicer frame, and a nicer bike in general. Add up what you think you might spend on upgrades and see if you can't buy a used newer bike for a similar amount of mulah.
as far as brakes go, I love disks too. hands down better for me than any other setup. I have avid bb7's on the Spot and the old 1x9 now and love them. for about $120 you can get the calipers and discs, add $20 bucks or so for nice cables, and pick up the cheap - o avid levers for like $12 and you'll have a pretty decent setup. Hydraulic is nice, but i couldn't afford it. I love my mechanicals.... not to say I won't upgrade in the future... but these are really nice. I also have a rock shocks reba on the Spot, and it does fine for me. yo ucan usually pick them up used for around $300... and rebuilding them is easy. the seal kit is not to cheap though. I have all the oils if you'd want them.
The Spot is a single speed hard tail 29'er... I have really enjoyed it around here. I have ridden some full suspension bikes, and while you can really go anywhere (pick any line downhill) the spot just seems to be more fun.
Anyways... not saying your old frame is not worth it, but you may want to look into picking up something newer.... it might get you more bang for your buck.