Are there roller lifters and cam that I can drop in my 340 with no modifications

They only show solid roller lifters on that web site. The offset pushrod holes don't negate the need for real short custom pushrods. After doing tons of research, I like the Hughes, if you want hydraulics. You will want adjustable rocker arms. They don't need to be roller rockers, but I have not recently seen new adjustable rockers for sale that are not rollers. Also, one thing nobody mentioned yet is that as far as I know all non-Magnum heads will need to have the pushrod holes elongated to clear the more angled pushrods. That's probably a job for a machine shop, for most of us. Well, you have to take the heads off anyways to install the lifters, so that might also be something else to think about.
Just put the ede heads on with the special push rods we had made , , Don't want to start pulling stuff but what the hell , want more HP