Hi Steve,
A bex bissel is an ideal tool for your domestic customers to use for small spot cleaning or extracting spilt drinks ect.
Don't take it personally but the bex machine really doesn't cut it in the professional field...
The vac unit is inadequate for total soil removal. 2 or 3 of the lamb amtec motors found in professional units working in line would blow a bex to pieces.
Lack of real heat, the bex just cant take the liquid to a high enough temperature to cut through heavy soil. Professional units use either in-line heat exchangers or in-tank immersion heaters, hot cleaning solution makes your job so much easier.
The spray pump in a bex is total useless, you would get more moisture from a foggy day!!, professional units that use diaphragm pumps (NOT INDUCTION) give a very accurate and powerful even spray at the tool end.
Cleaning solution capacity/ Waste tank. A bex holds a few cups of water, a professional unit holds about 40 - 50 litres, dito - waste.
Have a word with the nice guys at Ashby's
http://www.ashbys-uk.com/intro.htm . Lease or organise a bank loan to get you started in the right direction, this will not disrupt your current savings and have a negative effect on your cash flow, it's also beneficial for tax reasons.
Good luck Steve with your new venture!!
Peter