Yup. The cheapest is a torsion crank and shackles, and that will yield increased rear travel. AALs will increase rear ride height, plus beef up the rear springs, but the max rear wheel travel will not change at all (or may even decrease slightly). There are tons of threads comparing the positives and negatives of each - do a search on that one.
The typical max front T-bar crank w/out new UCAs is 1-1.5". The rule of thumb is that you can crank them so long as you can slide your index finger between the UCA and upper bump-stop. If you go higher your ride will get bumpy because you will be hitting your upper bump-stop a lot.
Bottom line - the cheapest is to crank your T-bars and install shackles (less than $100 including alignment). It will cost a bit more to go w/ AALs rather than shackles, but depending on your needs it may be worth the extra cash. Search for more info.