If you buy a Delta, Jet, or similar saw, the first thing you should do (after replacing the
stock blade) is improve the tension crank handle. You don't need an exensive quick release mechanism.
sells a handle that replaces your standard tension knob. It's the best $35 I ever spent. You can also
make your own by fashioning
a wooden handle around the existing knob. Either way, just do it. You'll be glad you did.
A riser block increases the distance between the two wheels, "rising" the top wheel. This means that you can resaw boards up to 12" thick. In other words, there can be as much as 12" of clearance between the top of the table and the bottom of the blade guide. Should you buy a riser block? I don't know. Here are some things to consider:
I added a brush to keep the bottom tire clean. It keeps saw dust from getting caked on the tire. Works great. You do not need one for the top wheel. You can buy a similar brush from Woodcraft, Lee Valley, or Highland Woodworking.
Cool Blocks replace the guides that go on either side of the blade. The Jet saw comes with blocks similar to these, but they wear quickly. If you have a Jet, then use the factory blocks until they get too worn out, then buy the Cool Blocks. If your saw has metal blocks, then I would replace them right away, especially if you are a beginner. The Cool Blocks are much more forgiving. If the blade teeth hit the metal guide blocks, then the blade will be ruined. You can also make your own blocks from hardwood scraps.
You do not need to replace the stock tension spring unless it gets damaged. Mine got damaged because I compressed it completely, which ruins the spring. I replaced it with one from Iturra Design. Note that there is a different spring for Jet versus Delta saws. The spring includes a sheet with the approximate PSI for the standard tension marks on the saw, which is nice. I think the spring is a little better than the factory spring, but I wouldn't replace your factory spring unless it is ruined.
I replaced the factory belt on my bandsaw with a Link Belt. You don't need to do that. I can't notice any difference in how the saw performs.
At least for a Jet bandsaw, urethane tires are a waste of money. The factory tires work fine. They do not need to be replaced.
See my other Bandsaw Articles.