Welcom to here from an old-timer.  Great to have new enthusiasts enter the realm of good audio.  You will benefit from decades of research which now provides us with affordable, high quality, gear.  Waaaaaaaay back, my "stereo" was mono, with sound coming from a home made box and a 25 watt, soldered, Heathkit, tubed, amplifier.  Just think of all the mistakes you won't have to experience by using the Stereophile to make informed choices.

Don't be a stranger!

Wattage ratings for speakers are pretty much meaningless. Most speaker failures are blown tweeters caused by an amplifier clipping because of insufficient power. 

Have you considered used speakers? The $300 you've budgeted for speakers can buy a lot more speaker on the used market. Check your local CL. You may come up with something really good for your money.

Blue Jeans cable has a very nice product line. They are not "high end" but they give good value for the money. Ideally both speaker cables should be the same length. With a maximum length of 15 feet the 12 AWG wire should be more than sufficient for your purposes.

Choosing speakers from reviews and the recommendations of others is like asking someone else to pick a wife for you. IMO you should never buy any speaker you haven't heard. Also buying a speaker with the thought that you can equalize or modify it to sound the way you want is IMO the wrong way to go. With speakers buy only what you have actually listened to and like.

Like pentode I've been involved in this passion for quite some time. My first amplifier was also kit, a Fisher KX-90 integrated tube amplifier. Currently I use tube (yeah, I still use tubes) driven electrostatic speakers.

Two publications worth reading are, The Complete Guide to High-End Audio by Robert Harley and Get better Sound by Jim Smith.

Here are two links below for each.. Welome to the forum...

http://www.amazon.com/gp/product/0978649311/ref=pd_lpo_k2_dp_sr_2?pf_rd_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=0964084945&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=0FZ42RKS51YY1GTXSP2T

http://getbettersound.com/

Many people, myself included don't think that anything with an 8" woofer can accurately be called a sub. Getting good bass is about moving air. You do that with high excursion or a large cone. Most sub woofers use a compromise of both. An 8" woofer means extremely high excursion with a consequently limited maximum output level. IMO a 10" woofer is as small as you should go. A 12" woofer or larger is even better. Two asymmetrically placed subs used in a distributed bass system will almost always work better than one. You'll get smoother room response because two subs tend to help each other to cancel nulls.