If this isn't going to be a rally car, rather a performance daily driver, I have to concentrate on the things that would otherwise turn shifting into a tedious chore. Bottom line, I want a final drive ratio that doesn't inconveniently leave me in the middle of two gears at speed limits, the most important being 50 and 130 km/h.
Using the values above and this website
http://www.apexgarage.com/tech/gear_ratios.shtml I came up with the following shifting and cruising points:
Shifting speeds @3000 RPMs with final drive ratio: 4,10:1
 1^{st} to 2^{nd}
 2^{nd} to 3^{rd}
 3^{rd} to 4^{th}
 4^{th} to 5^{th}

M46
 21km/h
 39km/h
 61km/h
 84km/h

M90
 24km/h
 41km/h
 61km/h
 84km/h

Shifting speeds @3000 RPMs with final drive ratio: 3,54:1
 1^{st} to 2^{nd}
 2^{nd} to 3^{rd}
 3^{rd} to 4^{th}
 4^{th} to 5^{th}

M46
 24km/h
 45km/h
 71km/h
 97km/h

M90
 27km/h
 47km/h
 70km/h
 97km/h

Obviously shifting points aren't set in stone, but the cruising speeds are...
RPMs @ common cruising speeds with final drive ratio: 4,10:1
 30km/h
 50km/h
 100km/h
 130km/h

M46
 2^{nd} @ 2300 or 3^{rd} @ 1500
 3^{rd} @ 2450 or 4^{th} @ 1800 or 5^{th} @ 1400
 5^{th} @ 2800
 5^{th} @ 3700

M90
 2^{nd} @ 2200 or 3^{rd} @ 1500
 3^{rd} @ 2450 or 4^{th} @ 1800 or 5^{th} @ 1450
 5^{th} @ 2900
 5^{th} @ 3750

RPMs @ common cruising speeds with final drive ratio: 3,54:1
 30km/h
 50km/h
 100km/h
 130km/h

M46
 2^{nd} @ 2000 or 3^{rd} @ 1300
 3^{rd} @ 2100 or 4^{th} @ 1550
 5^{th} @ 2450
 5^{th} @ 3200

M90
 2^{nd} @ 1900 or 3^{rd} @ 1300
 3^{rd} @ 2150 or 4^{th} @ 1550
 5^{th} @ 2500
 5^{th} @ 3250
