@Manfred - blues and rock - not metal
then you need something low wattage and maybe just one overdrive pedal.
If you have narrowed it down to a few amps and pedals you might want to own oneday, go check out youtube there's loads of videos with gear demo's.
Also try and keep in budget, some amps can get expensive.
Also test amps out at your local musc shop, to train your ear how to listen to what sounds best for you.