For what its worth, no knocks on anybody, just my experience:
I think you can purchase all the Deer Creek rifles directly from Deer Creek without going through a middleman. They have a catalog. I have only purchased a .36 CVA "squirrel" rifle from Deer Creek for my youngest son, transaction went just fine but I was buying CVA product... There are lots of posts dealing with Deer Creek's own products. If you think the middleman will give you additional service or help, by all means use a middleman.
Re: Blue Grouse... Before I bought my son the .36, I was looking at underhammers or a kit .32 for us to work on together. I looked at Deer Creek's kit .32s and noticed the ones from Blue Grouse, on Auction Arms, I think. The Blue Grouse guy was helpful and answered several questions I had concerning underhammers. Later, however, I made the mistake of asking him if his .32 kit was the same as Deer Creek's...his were a bit higher priced so I thought perhaps his might be from a different supplier, better components, etc. Suffice it to say, he was not appreciative of my inquiry. Much to my surprise I was immortalized in the text of his Auction Arms ads for awhile to the effect of "can you believe the guy had the nerve to ask me...." (My wife could have told him that if he had just asked her)
I can't honestly say I was a Blue Grouse "customer", as I ended up purchasing from Deer Creek directly. I can say, without fear of contradiction, that I WAS a potential customer, and will not be in the future.