You'll need to clear the rear sight on the #38...I have #22 high rings on my setup like that, but you *might* be able to get away with mediums. Depends on the eye piece...some are bigger than others, even at the same objective. I don't have any Leupold scopes, so I can't really say.
With the standard length #38, the rear eye will be right over the BUIS...so unless you get the EX or even longer one to get the scope more forward, it will definitely be something you'll have to contend with.
Here's a pic of the setup I'm talking about...that's a Simmons Aetec...it doesn't have a huge eye, and you can see how tight it is...not a lot of room there.
You could skip the #38, just get a 40L which is a lot lower, and you'd probably be okay with medium rings. It would be a couple of $$ cheaper too...there's about a $40 price difference between the 40L and the #38 if you get 'em new.
OOOPS...just read the LAST line in your post again...
The 40 or 40A will cause you the same problem of having to clear it with the eye of the scope...the height relationship stays pretty much the same whether the 40 is built into the swan sleeve, or just sitting on the rail.
BTW, if you want to sell that set of high rings, let me know...I could use another set.