A proper retail MV6 with the carbon effect climate control panel, leather recaros, Irmscher alloys and a manual gearbox is the perfect Omega for me! Try and get one of those if you can 
I have all that but the leather. To be honest I'm not too fussed for leather at all, it definitely looks better but I don't think it makes the car any nicer per-se. My BMW has it and it's damn cold in winter (until the heating has worked its way through the leather) and hot in summer. I wouldn't turn it down though if a set of sports MV6 leather came up at a good price, but I'd rather have sports cloth than leather armchairs -- hence why I've never had any interest in fitting Elite leather even though they're ten a penny and go quite cheap.
If you can get a retail (not ex-cop) manual gearbox MV6, in good condition, then you'll be sorted. Don't hold out for the leather cos they're mega rare and if you do find one chances are sod's law will kick in and either it'll be poorly maintained, or auto gearbox, or intergalactic mileage etc. They are very good fun to drive for such a big car, and although they do have their issues (most of which aren't too expensive to sort) they're great value for money being that late mini-facelift models (1998 to early 2000) often go for less than 2k.
The only thing the retail MV6 misses compared to the Elite is cruise control, and that's easy to fit with the parts typically £50 or less - I have it on mine. The rest of the stuff on the Elite such as rear blind and heated rear seats are nice toys but largely gimmicks in my opinion. All the important stuff is on the MV6 as standard, such as 4x electric windows, electric sunroof, climate control, trip computer/check control, HID headlights (very worthwhile). You also get better wheels (17") and better suspension than the Elite.
Good luck with your search!