Gravel Or Sand

sand, if you look at the pic posted in the Planted Tank group, I have a ton of plants, they all do fine.

Sand. Your loaches will burrow.

Sand. I started with black gravel and I personally feel it just gets dirty too quickly. When I had switched over to black sand my fish really livened up. I enjoy watching my Electric Yellow perfecting his fox holes by mouthing up the sand and spitting it out.

I also set up a friends 72 gallon fresh water tank a few weeks ago. He went with the natural look of sand so we chose 'Play Sand' from Home Depot. About 5 dollars for 50 pounds. Took a while to rinse/clean the sand prior to adding to the tank... the end result is just beautiful and crystal clear.

Sand takes a bit of skill when it comes to vacuuming.

Sand. Plants do fine in it. You can use a layer of laterite or flourite under the sand if you wish. I use sand over peat. Fish-wise, you might want to look at the water preferences for each species before buying them...for example, neons will do okay in 'tap' water, but will do best in soft, slightly-acidic-to-neutral pH. That might affect your choice of substrate.