Whatever hoist you look at to buy make sure your power at home ( if that's where it's going ) has the capacity to run it.
There are single phase and three phase hoists.
I went through all this 12 months ago when I bought my 2 post hoist.
3 phase is cheaper 2nd hand to buy ( generally ) than single phase but if you haven't already got 3 phase on then it can be very costly to have 3 phase done.
Spoke to a few hoist repairers and 3 phase can be converted to single if they are hydraulic hoists for about $600 or so.All the hoist repairers said that screw type are to costly to convert over to single phase.
I considered lots of 2nd hand and new single phase hoists in all brands and sellers and ended up buying a brand new Chinese made clear floor hydraulic one rated at 4.5 ton from a Brisbane seller for $2450.
Another $200 or so for hardwiring and 20 amp circuit breaker upgrade and its working great
No more cold hard concrete floors for me!!
And before anyone thinks that Chinese stuff is shit ( yes I also think the same in most cases ) then come and look at mine.The engineering is brilliant and looks over engineered to me for its rated lifting capacity.
The bloke I bought it from is a retired hoist manufacturer and installer and has been doing that for 45 years.He said the Chinese ones now are as good as any other make engineering wise and at least $1500 cheaper than any other make of the same type.
Off track here now a bit
If you want any tips and pointers from me Ken about my research and experience installing my hoist send me a PM with your ph number if you want and I'll give you a call.

I can't think what to write here so this will do.