Hopefully you mean DC - as you could just about get an AC/DC one if it were unsupported Chinese (which has varying results)
DC wise - you're either looking at a scratch start inverter from most of the normal tool people or you could look at R Tech - they do some machine around that size around that budget. They also come with pretty much all you'll need (except gas, helmet and electrodes)
Worth a look.
I've got their smallest AC machine - well pleased with it so far. Comes with the stick holder as well as the TIG torch too...
SIP have a bad name because of their MIG sets with design problems they've had for years and haven't done anything about.
Otherwise, in my experience, contact them with a problem concerning an item out of warranty and they don't want to know at all. They give the impression of being box shifter/rebadgers and not having much technical knowledge of what they are selling.
I'd be reluctant to buy a SIP welding machine. I've no idea what their expensive stuff is like but I wouldn't risk it myself.
RTech have a good name on here.
Parweld, I don't know. I've seen at least one review on here of a Parweld inverter which said it was good. It may not have been the XTI 160.