Problem with all these small spec setups is that it escalates into something bigger quickly. On Friday I bought a 1000W PSW inverter to power the lights in my home. It could not handle all of them (about 120 globes). Not that all will be switched on at the same time, but you never know. So then I went back to Communica and got a 2000W MSW. This worked fine until I tried to switch the garage lights on. The inverter bombed out on the fluorescent tubes. It could not handle them. So back I went and exchanged that for a 2500W PSW. This handles all the lights and 3 ceiling fans.
So the wife was happy, until Sunday morning, when we had our first loadshedding and the kids had to do homework. Quickly I had to include the whole house's circuits to power PCs and TVs too. Not part of the brief she gave me on Friday. Fortunately, with a bit of discipline, they can now power whatever they want, excluding the stove and geysers.
The point is, rather go big from scratch. No use having your PC running, but you bump into stuff in the dark. Upgrading is going to cost you more in the long run.