The Gaugemaster Prodigy Express is available for £124 from Hattons.
http://www.ehattons.com/stocklist/45/8/73/0/Gaugemaster_Controls_Any_or_multiple_scales_DCC_control_equipment_and_points_decoders/prodlist.aspx
Also the NCE powercab can be got for £131.
http://www.bromsgrovemodels.co.uk/pd-670066615.htm?categoryId=89
I went for Gaugemaster but bought the Advance 2, and I would highly recommend it if your budget can stretch the extra few quid. I was thinking about the Powercab
myself but was turned off it by the fact you can only have 2 locos in the recall stack. A problem they were going to address but not sure if they have done it yet.
Anthony is a Powercab user and he speaks highly of it, so maybe he can give more info.
A word of warning about using the Selecty with sound decoders! I had three 141/181 chips which malfunctioned on me and I have an idea it was something to do with the Select.
Search the Web for reports of Select problems, the list is frightening...
Likewise with the Dynamis, the general opinion is to steer clear of "Train Set" DCC controllers and go for a dedicated DCC manufacturer's system.