Okay, Sammy, let's clear up a few points. First, it's a Sceptre, not a spectre. A spectre is a spirit, a ghost, or an organization of James Bond villains. A sceptre is a royal staff.
Next, as EdBass pointed out, a cabinet can't "have too many watts" for an amp, because cabinets don't "have" watts. What cabinets do is handle input power, which is measured in watts. So it's not possible for a cabinet to have too much power handling. If you have a 60 watt amp, it might burn out a 25 watt speaker, but not a 100 watt speaker. It certainly won't burn out a 200 watt speaker.
Properly measured, a Sceptre with a tube rectifier will put out 60-80 watts. No way it's going to put out 117. Even if it did, that's only 3dB greater than 60 watts, so it's no big deal.
I don't know where you live, but 4x10" bass cabinets are everywhere these days, and 4x12 guitar cabinets have been everywhere since the 60's. I have no idea why you can't seem to find any. Old Sunn cabs are rare, so I'm not surprised that you can't get a good deal on one (whatever "good deal" means to you). However, the Fender era Sunn cabinets aren't usually all that hard to find. Look around for a Model 410H. I quite like mine.
I'm not familiar with the Ampeg 1510, but I think you'd be better off with a 1x15", 2x15" (like the Fender era Sunn Model 215), or a 4x10". Other guys like 2x12" cabinets. I have no opinion, not having tried any for bass.
Are you aware that the Sceptre is a guitar amp? That's not an issue, of course. I've used mine for bass many times, with excellent results. Just thought I'd mention it.
