Would like some opinions on tube rolling

My AudioNote preamp uses two 5687 drivers and two 6x5 rectifiers (I think that's what they're used for...). They are all Phillips. I would like to get a little more bass and mid-bass oomph. The unit is extremely detailed and transparent currently. I'd be willing to sacrifice a little (very little if possible) of that transparency to get the added warmth. Since many here have had good things to say about interactions with Upscale Audio I sent off an inquiry to Kevin, but haven't received any response from him yet. When I do talk with him, I'd like to have a little more background as to the possible alternatives and some input from those who have actual experience with the subject.
Thanks for the input
Vintage Tube Services! Andy is an expert not only in the custom matching of tubes, but knows volumes about the tonal qualities and history of N.O.S. tubes. Personally, I've had several bad experiences with Upscale, and consider myself very fortunate to have found a true expert like Andy at Vintage Tube Services (Tel.# is 616-454-3467).
I second that Fatparrot----Andy is a true expert when it comes to tubes, and a gentleman at that. He is there to answer the phone late into the evening, and he will spend time talking to you about your needs and what your trying to accomplish for your system.
You would be better served by surfing AA's tube forum and educuating yourself as to alternative tubes. Then buy what you want on eBay.