Scooterotica

Cezeta is your touring high torque set up man, but i wouldn't try to build a TS1 set up on the cheap.
I talked this over with cezeta this morning people are building motors on the cheap using parts from different manufacturers and then being shocked when nothing fits and their motors fly apart.
Read whats being posted on here and other forums and buy quality products save up if you have to it will save you money in the end.

pipe - JL3 or Taffspeed
g'box - Indian GP200
carb - 30mm, Dellorto VHSH/VHSA/PHBH
porting - Standard (with standard base gasket and thicker head gasket if required for 60mm crank)
piston - Standard or Racetour
crank - 60mm, AF race/MEC/MB Alpha (Dependant on budget!)
sprockets - 19/46
clutch - Standard 4 plate with uprated springs.

I'd also recommend a BGM stator, Iwis chain and MB chain tensioner.

This will give you a nice usable setup for touring.
I agree that you can't build a reliable motor on the cheap, but the parts listed above aren't the most expensive available but (usually) give proven reliability.