Baitcast combo for kayak fishing

If I had to have one reel only it would be a Chronarch. Get the G if he fishes salt. Gear ratio in the 7:1 range.

Rods are entirely subjective, one person will love how it fishes and the other will hate it. Shimano exprides are constantly out of stock because everyone seems to like how they fish. I have the 6’10 medium and it’s a little too light to be a do everything for bass but it’s a perfect inshore rod. They also make it in a 6’8 MH that would be perfect for kayak fishing.

For me it's the Daiwa Coastal 150 with a custom made 7' Medium Fast rod. I paid around $400 between the 2. Unfortunately my rod maker just moved to Tennessee. Sucks because I wanted another one.

I've got no experience with it but have heard great things about the Chronarch G if he's set on Shimano. I've got a Curado dc I love and have had a Curado 70 that was great as well.
If he doesn't mind branching out I love my Daiwa Tatula sv. Can cast light baits with ease and has no issues when casting into wind either. Has held up amazingly well too, better than my Daiwa Coastal.
As for rods I'm really liking the Daiwa Tatula elite line. For versatility the 7' m/mh ags elite would be hard to beat in that line, lure weight rating is 1/8-1oz and it handles that range extremely well.

Daiwa Coastal w/ Cajun Custom Atled rod

Another vote for the Daiwa Coastal SV TW on the lower end of your budget or a Shimano Metanium for a little more money if he likes Shimano. If you've got time for a little longer shipping I'd order a JDM Metanium, it'll be between $300 and $400 with shipping.

For rods I like St Croix, not that their aren't plenty of other good choices. They've got a Mojo Yak model that I'm really happy with but it's not one of their US made models.

Something to think about for kayak fishing is the length between the butt and the reel. The more I got into fishing from a kayak I realized that some of my rods were driving me nuts, and it was that length. Everything is closer in, and the longer rod butts would constantly bump my vest, sometimes making me think a fish was on the other end. A lot of rods, saltwater especially, have more length there and I never noticed it when fishing from a boat. I like about 12" or less from the reel collar to the butt and I ended up cutting down a couple of my favorites once I realized the issue.

ETA Missed that you were looking for length & power as well. I like 6.5' to 7', medium light or medium for flats fishing. The lighter gear makes it a lot more fun. The only time I use a medium heavy for anything is bass in lillypads.

St. Croix makes the Mojo Yak rod. It has a shorter handle also.

I use and would recommend either the Shimano SLX or the Shimano SLX DC on a Shimano GLF 6'6" medium power with a medium fast action. Short, compact little set up that I absolutely love.