I collect most of the wood myself.
I seldom use pre done wood.
Many species are high current plants, but they do well at low current.
I tend to prefer higher current than most aquarist, but it's namely for good mixing of CO2, O2, nutrients and the fish health(they get fat and lazy if they do not get their exercise and they eat better).
Several folks have done Caulpera Marine macro tanks etc that are very similar to FW planted tanks, it really depends on what species you use.
You can have all red plants in FW tanks also, many FW folks love Red color.
The red macro's here are very nice and cold water.
I have a 40 gal cube for them once my chiller comes in, keeping macros at 58 F is a bit different.
The wave action energy in rocky intertidal and soft sand sediments in marine systems is far more intense than FW systems.
A well run planted tank produces well over 100% O2 saturation for at least 10hours every day. The same is true for a marine macro tank that's well run.
Some nice things about the FW vs the marine:
Water changes are much easier
Dosing is much more forgiving
Live stock cost less
Pruning/gardening is required if you use CO2 and high light, best to go with moderate light and have moderate growth+ good CO2/nutrient levels, that gives you the most wiggle room.