Buying a Tube Amplifier

I have alot of audio equipment, my favorite set up is Simaudio moon W5.3 and P5.3 amp and preamp with B&W or Axiom speakers. I am listening to alot of electric guitar right now and can not imagine it sounding any better.

I have always wanted to try out tubes and I am going to. I want the first step to be something under 1K ish. I have been considering Antique sound Labs AV 25 monos.

Does anyone use or know these and can anyone give me some ideas of something that has really impressed them and what you are comparing them with?

Any help is appreciated
You may want to try a Cayin A50T or Prima Luna Prologue 1 used. These are nice EL34 based integrateds that are point to point wired or a TAD60 amp (can be used as a single source integrated) if you can fine one, also point to point wired. All of these at used prices represent great value, IMHO. If tubes are not your bag you could probably sell any of these and get your money back. If you like acoustic guitar you will like tubes. Since you are an electric guitar fan tubes may not do it for you. B&Ws are not known to be the most tube friendly speakers, not sure about Axioms. I have had Classe, McCormack, Forte, Superphon, and NAD SS amps. I like tubes better in general. I have a TAD60 and a refurbed Dynaco ST70 (also a consideration)now in different systems. If you want monos I might suggest checking out Quicksilvers (may be a little tough under $1K). I do believe any I have mentioned will have better build quality than the ASLs. You can have a lot of fun with tube rolling input and output tubes and stay broke in the process. It is a slippery slope my friend.
I would not waste any time or money on tubes if you mainly listen to electric guitar. I have Cayin units, also solid state stuff and believe me, you will be very disappointed listening to electric guitar on tubes. Stick to sound state, as there is nothing 'warm' in a steel guitar.
you might be able to find a Rogue Cronus used for about $1K - they are very good (integrated). if you really want to experience tubes, just getting tube power amps will only give you half of the 'experience' (in fact, if you're going to do half, you're probably better off going with a tube pre).
I bought some western electric made 12sl7 / 12sl7gt tubes. They are branded National Union. They are the very best sounding triodes ever made! Make sure you get the tubes made in 1944 / 1945
My first foray into tubes was an Onix SP-3 integrated amp that I bought from AV123 (now defunct). I still have the amp and when paired with efficient speakers works very well. It also responds well to tube rolling. You can probably find one used in the $300-$400 range.

I also own a Prima Luna Prologue One and a Cayin A88T. Both are superb amps, but considerably pricier.

Another way to go to get your feet wet is with a Yaquin Chinese made EL34 amp. These can be had new under $500 and for the money are pretty good.

Good luck and happy rolling!