The lower dash fusebox has three rails fitted, the centre rail is ign feed and should have several spare spaces but they will probably not have contacts in them to connect outgoing side so requires some fiddling
I reckon there will probably be a ign feed at the back of the radio but I haven't actually looked to confirm this
I have fitted an inverter in mine under the drivers seat but I am running a 2nd battery setup based under passenger seat and this second battery feeds the inverter with arctic flex leaving going onto 240V outlets in rear, all depends on what size inverter you want, I run a kettle etc of mine but if you only want a small one for charging batts etc you can get ones that plug into cigarette lighter socket that will give you a bit of 240v juice
Depending what tools you have some big manufacturers like dewalt sell a 12v charger that will plug straight into the cigarette socket but I'm guessing they will charge slower than mains I'm not 100%
Any questions feel free to ask I'm an electrician so this is my specialist subject and one of our other members does auto electrics
First step is to write a list of everything you need to be able to plug in and whether any of it needs to be plugged in at same time so you can work out the highest load you are going to need, total 240V load X 20 (approx.) = total 12V load. ie 1 amp at 240 equals 20 amps at 12 volt.