Long time griller, first time smoker

I’ve been grilling for most of my adult life now. I’ve mastered the propane grill. Burgers, steaks, chicken breasts all come out great. I want to take my back yard cooking up to the next level and start getting into smoking.

I did my first smoke yesterday, a whole chicken with a smoke box and cherry wood chips on my gas grill and although there was some trial and error, the end results were great, but I know it can be better and I have a few questions.

First for those that use a smoke box on a gas grill, should there be wood chips left? They went black and somewhat brittle, but I found I had to empty the box and refill it every half hour, then crank the heat back up until the new chips started smoking and then turn the temps back down.

Second, I used wood chips, but I’ve heard mixed messages about chips vs pellets in a smoke box, just wondering everyone’s opinion.

Lastly, I know the smoke box will just be a stepping stone to a real smoker. Probably leaning towards a pellet grill over a vertical dedicated smoker. Any recommendations on the cheaper end of pellet grills that still does a good job, preferably with the ability to open the flame box so I can still do some high heat searing for burgers and steaks?