I went with the 130D earlier this year and LOVE it! I've done All-In-One before as well as "build your own". The RSM tanks set the bar pretty darn high in regards to quality. Then if you factor in the amount of AMAZING customer service you've got a really winner on your hands.
Re: 34g vs 68g - What can you fit into the available space? What can you afford to purchase? What can you afford to maintain (Salt, testing, rock, sand etc). Go as big as you can afford and enjoy it.
+1 for what BigAl said
Coming from a complete newb (me :LOL: ), the RSM 130D has been a great tank to learn with. I have zero regrets except for maybe not making room for the RSM250 to start with.
That said, I've replaced nearly everything that came with it - purely by choice as others run beautiful tanks that are completely stock. For what it's worth, this is what I replaced and why:
#1 Heater - read too many posts about exploding RSM heaters. I do use it when mixing saltwater for changes.
#2 Skimmer - stock works okay but too noisy, plus I added a sump which opened my options
#3 return pumps - stock work okay but again are rather noisy and reputed to be on the warm side.
#4 Bio-media location - i.e. the Chamber 'o Death. If I hadn't added a sump the media rack from inTank would have been added so I don't have to reach into the CoD ever again.
#5 Lights - retrofitted stock hood with CREE LED's mostly to satisfy my inner geek but also wanted dawn/dusk dimming cycle, that LED 'shimmer' and the ability to keep any SPS coral.