4 speed upgrade help (close ratio)

Hi all,
Ive just taken delivery of my new gearset for my 4 speed. Its a Tran-x gearset, straight cut jobbie.. comes with bearings and gaskets in the set as well while i strip down an old box i have for the housing layshafts etc id like to make sure all the other internals are in good nick as well.. so..
can u still get the following?
- new Synchro rings
- Synchro sleeves
- Roller bearings
and also while im at it ive been looking on a few sites and places like palmside sell those gearbox tops
whats the purpose of these? do they assist with a race box?
also is there anyother things i should upgrade in the box while im at it to make sure my hard earned doesnt get stopped by a worn out or part not up to the task?
Cheers
Matty
Ive just taken delivery of my new gearset for my 4 speed. Its a Tran-x gearset, straight cut jobbie.. comes with bearings and gaskets in the set as well while i strip down an old box i have for the housing layshafts etc id like to make sure all the other internals are in good nick as well.. so..
can u still get the following?
- new Synchro rings
- Synchro sleeves
- Roller bearings
and also while im at it ive been looking on a few sites and places like palmside sell those gearbox tops

whats the purpose of these? do they assist with a race box?
also is there anyother things i should upgrade in the box while im at it to make sure my hard earned doesnt get stopped by a worn out or part not up to the task?
Cheers
Matty