1989 ski nautique rebuild

When you say rebuild, do you mean freshen up or full rebuild.
If you are just re ringing, bearings and gaskets you can buy those parts most anywhere and some of the large internet sites do have very competitive prices. Summit, Jegs, EPW.

If you need rebuilding done, boring and honing the cylinders and maybe grinding your crankshaft you are better served normally to find a very good machine shop in your local area. Ask around and make sure you have good feedback from real users of the shop you choose.
The machine shop will give you a better deal on the machine work if they supply the parts so your package price will be better if they supply the parts, or it may be a little higher but the key important part of them ordering is they have to stand behind what they sell you.
The pistons/rings/bearings will fit or they will fix it no charge.
If you mail order and the pistons are the wrong size the bill is on you to get the right parts. Freight can eat you up if there is any mistake at all and you loose a lot of time.
Good references are important.
To build a high quality engine the shop needs the pistons on hand as they finish hone to get the oversize exactly correct. Like it or not pistons will very slightly from one box to another.
Sealed Power supplies Original Equipment quality parts I would trust, the brand you choose may or may not equal OE quality.
If it helps brands I trust, Fel Pro gaskets, Clevite or Federal-Mogul/Sealed Power Bearings, Sealed Power Rings, Sealed Power, Mahle or Silvolite for pisotns, Sealed Power, Crane or Competition Cams for Camshafts. Melling or Sealed Power for Oil Pumps.
Hope this helps and this is just one guys opinion.

Ok, so the engine was ran low on oil and spun a rod bearing. Im having the crank grinded and the rod on the bering that spun needs work as well. im reusing the pistons but would like to get new rings which is why i need to hone the cylinder (so they seat properly). as far as compression goes one cylinder had 120 and the worst was 103. unfortunately i didn't do a leak down test. The pistons came out fairly easy and the rim and the cylinders didn't look to bad either. im trying to do almost everything myself right now because money is so tight.. the rebuild shop recommended i replace the cam as well so need to find the reverse rotation cam for the best deal possible. Thanks for all the input

Old school training said to always hone so the rings can seat.
Modern rings can seat on a very smooth surface. They don't need a new hone unless you have damaged the cylinder in some way.
Even GM has a tech bulletin out saying the cylinders do not need to be honed on a rebuild unless there is damage.
Even in 89 your engine should have had Moly top rings, these do not wear the cylinder like the old school cast rings and they seal on a very smooth cylinder. If your cylinders are damaged they need fixed, maybe even bored oversize, if the old cross hatch is visible and not damaged re ring with moly top rings and build your engine with no hone. Modern rings like a very smooth cylinder and will seat fine.
How many hours are on this engine? If the cam and lifters are smooth and clean they may be fine but would need to run again on the EXACT same lobes they came off of. Lifters once broken in to a lobe need to stay there if you plan to re use if you mixed your lifters when you removed them they can't be re used. The rod bearing farthest from the oil pump fails first if you have oil starvation, the rest of the engine might be fine or similarly damaged depending on the amount of oil starvation that occurred. Assess your parts and then make decisions.

If you have the 1.23 reduction transmission then you do not have a reverse rotation engine.

Thanks for the help guys i've just found out that my engine is standard rotation. Its the 1.23:1 which rotates right hand at the prop not the engine. Anyway that makes everything much cheaper thanks again for clearing that up. I could have made an expensive mistake.