Wow, where to start.
1 do not expect clever word play in the lyrics, neither Yes nor Rush have the literary talents and word-smithery of Peter Gabriel.
2 If you like the big opus type prog rock, there is plenty here for you.
I would go with Yes first as they are british and you will pick up some links back to a common route with Genesis.
The Yes back catalogue remsatering has been done with sympathy and constant precision by Joe Gastwirt at Ocean View Digital, the same ,sadly, is not true for the Rush remasters.
Start with 'The Yes Album' , the oldest CD that I am prepared to recommend (I have had them all on cassette, vinyl or CD) and listen to where they were trying to go with the keyboards before Rick Wakeman joined them. Then move on to either or both of 'Close to the Edge' or 'Fragile' both a re superb and them go to 'Relayer'.
After this they kind of took the trip too far and the double album' Tales from Topographic Oceans' is like the curates egg, in that it is good in parts but about 40 minutes too long
. After this band changes and line up squables took the band in more pop orientated directions. My brother loves this chapter in the history of the band with the same energy that I reserve for its revulsion.
There are some side avenues which should be investigated in terms of solo work and projects.
'Heaven and Hell' by Vangelis is another opus prog homage to classical and has the moving voice of Anderson on the track, 'so long ago so clear'
Anderson's own album 'Olias of Sunhillow' is also very good, if now very hard to find.
I can also recommend 'Fish out of Water' by Chris Squire and the first 3 albums by Rick Wakeman, sadly none have been remastered and in dire need of such; 'The 6 wives of Henry VIII', ' Journeyto the Centre of the Earth', and ' Myths and Legends of the Court of King Arthur and the Knights of the Round Table'
Rush, well the first 3 albums are better on remaster than on the original release; 'Rush', 'Fly by Night' and 'Caress of Steel'. The original eoponymous album which is short for the money (less than 40 mins IIRC) is influneced by Led Zep 1 and also bands like Budgie and Montrose. There is a line up change and from 'Fly by night' we start to feel the longer compositions and epic opuses developing. Rush , being Canadian always have that North American feel about the presentation, kind of Stadium rock meets Americana, but never the less make some tunefull tracks, although lacking in the complexity of either Yes or Genesis.
The 4th album, '2112' has been poorly remastered, I had both versions but kepth the original, which also holds true for the 5th studio album, 'Farewell to Kings'. I am told that the Musical Fidelty pressings on Gold discs are the best, but I have not found them on sale at an affordable price. After farewell to kings the songs start to become more commercial in length and composition which made them more FM friendly, but therefore less prog.
There is much to love with both bands, so enjoy