I am seeking fashion tips and advice on the following items:

Wearing a crew/v neck t-shirt over a short sleeve shirt - Can it be done? The idea behind it is nerd style?

Secondly where can a get a decent male scoop neck jumper that can be worn with a shirt and tie underneath?

Finally Suits - good but not bank breaking for weddings and christenings. two piece/three piece.

I thank anyone in advance for any help and tips.