yea. a good audio set-up can range anywhere from.... eh... we'll say....
Head Unit:100-300 for a decent to good cd/mp3 player headunit. since your a noob(mp3 cd players allow you to use mp3 or data cds in the cd tray along with regular cds that you would buy from stores and what not. mp3 cds can handle more songs, but like stated, can only be played in mp3/data capable head units/players.
Door Speakers: because its a 93... it only has spots for 4 speakers and no tweeters. one in each door... and one on each sail panel. all are 6.5". good speakers range from 60 a pair... to 150 a pair... i have alpine type r 6.5" all around in my 94... also has 4 speakers... and they sounded amazing alone... with a headunit to adjust bass and treble levels it runs perfect for what you listen to... the type r's have very good bass output for such small speakers. they cost me $83 a pair... which is amazing prce for the quality... definitely my number one preferred speakers.
Wires/Install Tools: Go to walmart... pepboys... or anywhere that has car audio parts and get some new wire... prolly about 50ft for all the speakers if your just doing speakers. 50ft will be plenty... wiring harnesses for new headunits are like 6 bucks i think. and some terminals for doign the wiring are like 3 bucks for a pack. its pretty simple one you get used to doing it.
as for subs and amps... it all depends.i thnk if you start off with the type r's or a similar speaker all around... youll be happy regardless... even if you decide to get subs and an amp later on... they will still keep up their performance. if you got any questions about install... or places to find speakers cheap.. pm me. audio has become my specialty... lol.