If you’re set on building a bench, take the time and expense to make it right. You don’t need to make it out of butcher blocked hard maple, but you really should use hard wood. Oak works well and it’s fairly cheap. You can use fire or pine for the verticals, but don’t use it for anything else. Softwood will twist and bow on you and you’ll cuss at it every time you try to assemble something because it won’ be flat. I’ve done this three times now, because I went cheap twice. My current bench works very well. I build it 28” wide by 7’ and it’s about a half an inch shorter than my table saw so I can use it for an out feed table. On one side I have an open tray for ‘stuff’ I use all the time, like scraps of sandpaper, glue scrapers, straight edges. I built it sturdy as hell with 4” fir legs and 4" X 1" Red Oak for the table top support spreaders 12" O/C and 3/4 MDF screwed to the spreaders. I then use ¼” hard board for the top, screwed to the MDF and it's edged with oak. After a few months or so, I’ll just yard out the hard board and screw a new sheet down. This way I don’t feel bashful about beating the hell out of the top as if it was a pretty maple top. I do all my glue ups on this, stain on it, sand, port work on cylinder heads, file ring gaps, whatever. I also installed bench dogs and a screw on the bench, but I never use it. I usually just clamp my stuff down with quick clamps if I don’t want it moving around on me. I also have good, lockable casters so I can roll it out of the way. I buy my casters from Woodcraft, they are excellent.
"......The wisdom of life consists in the elimination of nonessentials." ~ Lin Yutang