purchased a jacuzzi perfecta and the tank was broken,can i purchase another tank for it?lowes sells just the tank for other toilets ,will they fit mine?

I have two bathrooms back to back. First leak was the shower drain, big black pipe under the floor. Pipe was cracked so had it replaced and then found toilet in other bathroom was also leaking under the house. I had that big black pipe that attaches to the floor where the toilet sits replaced as well. It had an actual hole at the top lip and water just poured over the edge, probably for years. Then had new toilet installed-total so far over $1K! Big deal to go and work under the house, crawl space only about 12". A few weeks later, toilet leaks from bolts attaching the tank to the bowl. First plumber won't return calls so new plumber takes apart toilet and finds the bolts and the seal caulked and says the first guy din't "know what he was doing" to caulk a new toilet like that. Replaces seal and bolts and now the toilet doesn't leak where we can see it, additional $200 but this plumber won't go under house to check for additional leak but have terrible intermitent smells so... Go under house myself again and find that the toilet is still leaking! After 3 flushes, the water pours out behind toilet and down the wood subfloor directly behind base of toilet. No water can be seen standing in the bathroom, can't feel it on the floor but can only be seen from below. Now have puddle about 2 inches deep under the house. Naturally I don't want to call either of these plumbers again and they were recommended. Now what? Pick out of the phone book? Take the toilet off myself? Any ideas what is going wrong? Thanks in advance for any help!