As DS said, plan for wind. We would suggest for late March to April even with staying in Port Aransas to also consider booking a guide that fishes down south in the Laguna Madre, Baffin, and/or the Land Cut areas.
Through mid-March to early April if the winds are severe many LM,BB, LC guides will run to the Land cut and fish the protected ICW.
Pert near a guarantee you'll limit on solid 18"-22"+ trout and lots of slot,eating sized black drum on live shrimp, and always a good chance at reds off in the Meadows on the way back to the dock.
Your time frame for the Port A area can do well, just expect wind and expect the size of the trout to be smaller overall and not as many drum caught. Reds, possibly limits in that area at that time. The trout bite is usually overall sporadic until mid to late April in the Redfish & Aransas Bay areas in part due to the wind.
As for your last comment, for fishing the Port A area proper, we'd suggest mid-May into July, while your time frame mentioned is ideal for a pure fish haul down south.
Just a suggestion, whichever way you go, hope you have a great trip.
Gonna be using a guide, so what ever bait he thinks will catch fish. I was just wondering if the late March/early April was a good time to be going to catch a lot of fish. If responses were negative to moderate about that time of the year, would probably save my money and go at a different time of the year.
Make sure you have a plan for the wind.
What type of fishing will you be doing?? Live Bait, artificials,etc.??