Could you recommend some parts?
 

Hello, I have a trek 8500 hardtail frame. I want to do some longer rides maybe sections of the GDMBR next summer. My frame is nearly new (it was a trek warranty replacement). However almost all the other components are really old (off an older trek 7??? or something like that).
Its all 8 speed shimano stuff. Deore LX. The only drivetrain components that are new are the cassette and new truativ cranks. It has been adjusted by me and friends that own a shop and the components on it just will not work properly. They go out of tune within one ride.
I am just not sure what would be best to replace the parts with. Im tossed up between sram and shimano. My roommate has a brand new x7 derailleur I could buy for really cheap so Im thinking about going that route. Im also considering just buying replacement Shimano stuff. I would also like to upgrade to some disc brakes. Im thinking mechanical avids or something along that line.
Im also an unemployed graduate student so cost is certainly a factor here. I will be slowly piecing things together over the fall and winter until I can do my build.
I would appreciate suggestions on to how you would build this bike and what parts you would recommend. If you know the price and good retailers that would be even better.
Thanks,
Dan

Did you replace the cables and housing yet? If not get the x7 from your bud, thats a good start.

Price Point is a good source for good prices on good parts. I'm pretty sure they have some SRAM 8-speed shifters to go with "your" X.7 (good derailleur, BTW!)

Also, it seems that the x7 is a 9/10 speed part. Will this be compatible with a 8 speed cassette? Should I upgrade to a 9 speed cassette if not? Or should I just find compatible 8 speed parts?

http://www.rei.com/product/808775/sr...ear-derailleur
That is the derailleur. You can see whay I have it listed 9/10 speed. It is listed by rei as a 9 speed but the lettering on the derailleur says 10. Any idea what it actually is?

So I have started to piece some things together.

I have or have ordered these parts:
SRAM x-7 9 speed (although the product says 10) rear derailleur
http://www.rei.com/product/808775/sr...ear-derailleur

SRAM X Gen Front Derailleur 9 speed
http://www.ebay.com/itm/380362391242...m1439.l2649And I am thinking of ordering the Sram x7 shifters. I like the ones with the gear selector window like these:
http://www.ebay.com/itm/Sram-X-7-Tri...item45fc85abf1

Im still not sure if there is a particular cassette I should order. I dont know much about the differences except for the gearing. I am also unsure about what 9 speed chain to order and if there are particular cables that would be recommended for a build of my style.

Also I have some standard v-brakes on the bike. I was going to upgrade these to a disc setup at the same time, maybe some avid mechanicals but I spaced it and didnt think that I wouldnt have the hubs to support them. So I plan on upgrading all the drive line stuff and either putting new replacement v-brakes on or waiting till I have the money for a new wheelset and disc brakes

Do my plans sound like I am heading in the right direction? If not please make some suggestions and help me select better parts. Thanks!