125w is not much at all for a bass rigg. Thats a practice amp. My bass player plays an SWR SM900 which is 900watts at max. Competing with 150W guitar riggs, which is about as powerfull as guitar amps come (expept for a Marshall Major, naturally), you need alot more power for bass.
I dont know about the Marshall but for 1000 Pounds you should be able to get a real nice bass rigg. SWR, Ampeg, Etc... I dont know whats available over there. I never heard of Marshall making any particularly decent bass amp. Maybe. But I never heard of it. Look at head and cab deals as opposed to just combo amps.
As far as looking cool, believe me, once you get a really great sounding rig, itll start to look cool to you awefully fast.