A basic truck inner tube is what is inside your round tubes. Unless you do something crazy these type are almost indestructable. Just make sure you don't put lures in the pockets with exposed hooks. You also don't want to leave them fully inflated for long periods of time. You should be able to pick up a round tube for no more than $50 or $60. If you were to buy an inner tube seperately it will cost you around $20. Plus the cost of that kit, you're really not saving any money. If you're looking for durability, then go with the round tube. If you want to be a little more comfortable and be a little quicker, go with a pontoon or u-tube style. Also, whichever you go with, if you buy it from a reputable company, they will have warranty coverage. This way you can replace something(sometimes the whole unit) if something fails.

Oh, and yes, they do get holes in them and worse. I left a Zara Spook in one of the pockets one time in my round tube. Made a small hole and I lost air very slowly. I also had a bass make a charge at me with a mouth full of chug bug in my Nav4 with the same results. Nothing life threatening. But it did put an end to a day of fishing. I'm sure someones got a horror story or two.