Hi guys I'm looking at ordering some wheels 15x7 revolutions and I need to know what I tell him whilst ordering them I have no idea about offsets or anything of the such any help would be great

Also I have rolled guards if that helps

For MK2 Escort?  In that case ET12 is commonly used, as it gives a few mm clearance between the tyre and the bodywork when using 195/50R15 tyres (which keeps the speedo accurate).  With rolled guards you can go a tad more.  ET06 is a common offset used in the UK for 7" wheels, such as the RS 4 spoke replicas, and some owners here have reported rolled guards are a must in that case.

Yep +12 offset
I had 16x7 with 205/40/16s and they didnt scrub

yet +12 is the go, ive got 15x7's with 195/50R15's and they fit well. could go out to +10 or so if u wanted.
 
fighter the +6 used in the uk is only on the 13" wheels which ofter require a narrow tyre stretched over the rim to make it fit properly.
i currently run a 8inch wide 13" rim that i run at a -8 offset. but also stretch a 175/60 tyre over said rim to keep the tyre in the guard,

Mish
fighter the +6 used in the uk is only on the 13" wheels which ofter require a narrow tyre stretched over the rim to make it fit properly.

True, but it doesn't matter how tall the wheel is (i.e. 13", 15" or whatever) when it comes to specifying offset.  From what I can gather, UK wheels are often made to keep the backspace identical with the factory figure; hence the ET06 on the 7" RS 4 spokes vs. ET19 on the 6" factory versions (giving 108mm backspace in both cases).  This is sensible, as it ensures that the wheels won't foul struts etc., although it can make it awkward to fit tyres as you say.  ET12 works well with 7" wheels on Mk2 Escorts though, as they neither hit the struts or cause the tyres to rub on standard bodywork even when fitted with the correct 195/50 tyres.  I can't yet say definitively whether they will rub on the front spoiler, although I will eventually find out the hard way....