A good inkjet print will be better than any laser print, period.
Laser is good for medium volume production, and as a result of it's increased print speed over inkjet, it gives up some quality.
Inkjet is the slowest process of the bunch, but NOTHING can beat its quality. If you really want to see what inkjet is capable of, google "Giclée".
And at the opposite end of the spectrum, you have offset printing, which is the fastest by far, but the absolute lowest quality (it's not a process that any of us can/will employ, but I just wanted to toss it out there to help better exemplify the quality-to-speed ratio of each).
We have a $15K Konica digital press (laser printer) and I can still get equally good if not better prints from a $400 inkjet (and the paper options are far more plentiful).
If you're doing 200 or so covers, go inkjet. If you wanna do 500+ at once, then laser would be the way to go IMO. The common misconception seems to be that laser printers produce better quality prints since they tend to be more expensive on average than inkjet. You're not paying for quality. You're paying for efficiency and the tech required to make it happen.