Will 987 go into 986? HELP!!

[Exy]

Hopefully one of you technical chaps can help me out please.
I have an 04 986 2.7 with Boxster S II wheels fitted;
F 7.0J x 17 ET55 205/50 R 8.5J x 17 ET48 255/40

The Tequipment brochure for the 986 gives the following options;
F 7.5J x 18 ET50 or 8J x 18 ET50 225/40 R 9.0J x 18 ET52 or 10J x 18 ET47 265/35

And the Tequipment brochure for the 987 gives the following dimensions for a set of wheels;
F 8J x 18 ET57 235/40 R 9J x 18 ET43 265/40

Seller says "No problem" but my OPC says NO.

ET W " ICL OCL MODEL
55 7.0 143 32 986 BOXSTER S II 205/50
50 8.0 150 50 986 SPORT TECHNO 225/40
50 7.5 144 44 986 CARRERA 225/40
57 8.0 157 43 987 BOXSTER S 235/40

48 8.5 154 58 986 BOXSTER S II 255/40
47 10. 172 78 986 SPORT TECHNO 265/35
52 9.0 165 60 986 CARRERA 265/35
43 9.0 156 69 987 BOXSTER S 255/40

The rear clearance is OK as the SPORT TECHNO sits further out/in, but the BOXSTER S front wheel sits in a further 7 mm than the TECHNO.

Will this be a problem clearance wise??
What effect will the different offsets have on handling??
I really wouldn't feel comfortable with "It should do alright".

7mm spacers anyone? Any advice appreciated.