Gernis, Pressure Cleaner/Washers, Sand Blasters

I've been doing a bit of pressure washing recently - concrete, tile, and bitumen paths, boulders around pool landscaping, brick walls, and tried to do the eaves, windows, screens, and sills with varying success.

I eventually hired a petrol driven one but used a neighbour's light electric Karcher a bit at the beginning.

I'd love to buy a petrol one and have read other forums, and it seems Gerni has the best rep, followed by Stihl, then Karcher.

I wonder whether they are ok to use on car paint regularly, or too harsh on paint.

I have also been wondering about using them to strip paint from external walls of house.....either with soda or sand blasters.

Would appreciate any thoughts on what type of machinery people have had experience with in this field. If I get something, I'd lean towards heavy duty, industrial as the sprogs may be doing a few renos over the coming years.
I've spent the last 14 years managing varies Kennards Hire businesses. While I'm not in the general hire anymore...... :) The brand they still swear by is Aussie pumps based at castle hill in Sydney.

They have a million and one attachments and can vary output by changing tips rather than buying a bigger machine. The issues with the karcher and gerni units where always poor build quality mainly the main seals leaking after little usage.

A hire company machine does need to be profoundly more robust than one used once a month for an hour as there machines could be used 5 days a week flat out all day.

The electric aussie pump unit is reasonably priced from memory but its not a $200 bunnings special.
As i said before, I haven't been in general hire for some time. The hot water washers where huge with large boilers required for the steam.

Again the aussie pump unit was the model used in the branches. I can check with some of the guys in general what there buying? but from memory they where in the 7-10k range while the small electric 1500psi is about the 1.5k range.

photo of the hot water unit - Washers&lvl=2

apologies for the brand placement but I don't technically work for kennards hire :)
Thanks Andrew. I'll give Aussie a call and have a chat to the guys at the local hire joint for their views. I don't mind paying for something that will last. Often when you sell something of quality, you end up ahead with the depreciation claims.