Chris,
You are asking for more trouble than you can imagine. Go back up the page and read DrewE. If you power the computers off a single inverter that is sourced by the house bank, you have a chance, (only a chance) but you had still better test things. You are about to get bitten by the infamous Switcher Bug. There is a defense but it is expensive. Few things have real transformers any more. These are expensive iron and copper parts that avoid aliasing. Aliasing is when two switching devices get on each others case and you can end up with results that defy any simple explanation. If you have two, you may have a problem. If you have three there is a very good chance you will have a problem, but if you have four stacked together it is nearly a certainty.
Your converter is a switching power supply.
Your UPS has a switching power supply.
Your inverter is a switching power supply.
Your computer has a switching power supply.
You only need two of these to disagree and nothing works. The house bank will be a big enough buffer to usually (not always) keep the things that it and the converter power happy, but past that.....
Even if you blow the extra money for a "Pure Sine" inverter, you can still have problems.
Good luck guy.
