Your budget is the crucial bit on this.
Seriously it is......and mind that you don't need eight yards unless your fabric is very narrow. They sewed two lengths together to get the width necessary once warp weighted looms were no longer in use, so it's doubled up.
There are generally three weights in use for 'wearing' tartan. Used to be more, but there are fewer mills now.
The modern heavy weight is what's used for kilts.
The middling one is often used for dress stuff, for kilts for weddings and dancers, suits and the like.
The lightweight is generally for stuff like finer clothing pieces, scarves, dresses, etc.,
https://www.lochcarron.co.uk/fabric-cloth-shop/tartan-fabric
have the best range, but they are expensive.
HEAVY WEIGHT TARTAN FABRIC
scotchtweed.co.uk
have nowhere near as much variety but are a lot cheaper, often by as much as a third.