Of all the online dealers that sell astronomy gear Agena Astro is my hands-down favorite.
They're a big dealer and often have stuff in stock that others don't.
But best of all, they're the personification of customer-centric.
Their pre-sale advice is easy to obtain and they're very honest. I was actually told on one call not to buy something I thought I wanted.
And after you buy something they're just as eager to help if you don't understand how something works or, dog forbid, something breaks.
PHONE (562) 215-4473
EMAIL support@agenaastro.com
A good list of other astronomy retailers1) is available at TelescopicWatch.com. What they say about High Point Scientific is all correct and I highly recommend them.