New suit...hope it has taped/glued/blind stitched seams. If so...you'll be good for a coule of hours...I would suggest 7 mil boots and 5mil gloves. Better to have warm/sweaty feet...IMHO as I assume you only have 3 mils.
New suits are great...won't start leaking (pinholes) for a while...enjoy it!
A well-used 4/5 with 7 mil boots and 5 mil gloves boots got me through the VB winter. A hood too, of course. The water here got down to 37 this winter, but air temp of 38 was the coldest I was out. That's almost "tropical" compared what our northern friends deal with. Wind can be the killer. I'm colder after I get out of the water and am walking back to the car.
Expect to be in for even less then 30mins and not being able to feel your fingers or toes with any boots or gloves under 5mm. The coldest I've had up here was when I took off my gloves and my hands were purple about 1min after I took the gloves off and then Thursday my hood froze while I was wearing it in the water. There were icesicles hanging off it too!