Welcome to the club!
What you will find is many of us have "our" preferences as far as speaker cables go. I think Spike has the right idea which is to look in to some DIY type cables. There is also one other place you can look and I think he is in your general area and that is DIY cable. I think Kevin's site is diycable.com. He does sell some of Jon Risch design cables.
Basically, DIY "stuff" is cheaper in price but not necessarily on quality. I have bought power cables from him and was very happy. The thing you need to understand about cables, specifically interconnects and speaker cables, is they are tone controls. Yes they will “change” the sound you hear. Sometimes it is just subtle differences and sometimes dramatically different. This is dependent on the equipment, the amount of noise they may or may not pick up along the way, and of course the actual connectors.
My suggestion is to go slowly. A dealer, no matter how honest, will sell you what he has in stock because this is why he is in business, i.e. to make money. I would just do one thing at a time. Either start with just your front speakers (assumption here) if you want to explore speaker cables first or start with the interconnects (IC’s) between the CD player and the preamp or receiver. This will give you the most “bang for your buck” and where you will hear the difference.
Most of the other places these changes/upgrades will be subtle but noticeable. One other question I would ask your dealer and this is can I try these out at home? This will tell you definitely what changes in sound they may offer in your system.
We are all here to help and have been there. I have a mixture of different makes of cables in my system. Some were inherited and some were purchased. Yes, in a perfect world it is nice to have the same throughout but reality dictates that we are not “rolling in money”
and compromises are the name of the game. You just want to put the best you can afford where it will make the most impact.
Good Luck and welcome again
Jeff