Peavey headliner 2x10 or Markbass traveler

Depending on where your priorities lie, you are really comparing two different animals here. The MB costs 3x as much (unless you're going used) and weighs about 20 lbs less than the Peavey. So if price and weight matter, you should consider these factors. Then there's the issue of tone, which is a personal preference and will be affected by your amp. Try them both if you are able with your own amp before buying. I've demo'd both in the past, and found the MB to have cleaner lows and better overall tone.