I asked the same question about Marbles sights a month or so ago on this site. All of the knowledgeable guys here said the Marbles sight is not as good as Marbles would imply for their "old" style sights, so I steered away. Some have said the receiver sights go better with post war guns and tang peeps with prewar. As much as I like the tang peeps, I'd agree with them and went with a receiver sight for my 1954 EG.
I've seen the Lymans and you wouldn't go wrong, but I bought a Redfield 70 reciever sight from Loggah and am VERY happy with it, and the Redfied 70 is period correct for 50's guns and maybe earlier and seem to go about $100 on eBay or Gunbroker and with some of the sight collectors, maybe a little more.
No notch req'd in the stock, but did shorten the vertical travel screw by 1/8" however to avoid a mark.
Here's a pic of it
Perhaps get the reciever sight now, and wait to score a tang peep at a good price down the road if you decide that'w what you really want--the tang peeps can get pricey at $ 200.oo or more unless you shop a lot or luck out.