Bluetooth speakers

[Notapadawan]

I'm looking for a Bluetooth speaker that I can hear over the outside noise in my 69 Chevy C20. Needs to be LOUD, clear sound, for under my stock bench seat, and be portable. Working on a budget of $400 (+/- a little) max. I've seen some that actually come with a microphone which could be useful because I can use it for my BMX freestyle teams shows (our next one is the F*ck Cancer Car Show here in Tulsa). Let me know what y'all recommend

Mildred (my truck) is pretty loud. Rebuilt 350 pushing around 375 at the wheels, shortened exhaust comes out the side just behind the cab, and I have a tendency to lay on the gas AFTER trading my sm465 for a T56 from a buddy's wrecked Viper. I'm doing upgrades slowly as I can afford them but here's my list so far...

T56 6 speed transmission
Rebuilt 350
Painless wiring harness
Disc brake conversion on the back
Found the parts to convert the front in a junkyard last week and smashed then up but haven't had time to install them yet
Patched the floor panels, sealed it, painted it
Installed Siless Sound Deadener on entire floor but still need to do the doors
Ordered new seals for the doors but still waiting on delivery