Buy one if you want to ....no probs with that..Lie Nielson do a major bench with some awesome vice fittings etc...$2000.00.
But in all honesty, there are so truly easy to make and you can design it around your own needs. I thought it was a really good project to do and enjoy the results.
You will no doubt after you have built it find improvements etc and next time it will be even better.
Check out the ones for sale and use their design specs regarding wood choice and arrangments etc
My table is 4inch by 4 inch square softwood base with hardwood top made up of approx 9inch wide planks approx4 inches thick, can even laminate base layer 2 inches softwood to 2 inch thick hardwood surface layer, all glued and dowelled. Last for years.
But to answer you question....I used 40mm thick top layer of french oak...simply because I have loads of it to hand, tung oiled, seveal times, it seems to be wearing well.
Price some up and you will be surprised how cheap it may be, especially for the small amount you will need for a table top.
The moving finger writes....and having writ moves on...nor all thy piety nor wit shall lure it back to rub out half a line.