yes, there are a lot of versions of it and similar rituals.
The first consideration is why ? Why do you want to practice it and what do you hope to achieve? That should be the first entry in your LBRP 'diary'.
Depending on this, should help you decide . I would not recommend youtube anything off hand, but would recommend Regardie. It depends whether you are just a curious reader or are actually going to do some practice?
"The instruction in Regardie's book on LBRP seem somewhat different from other instructions, so I was wondering, if there are variations on LBRP, and if so, how and why?"
Even that 'narrowed down' question is a big one. One simple thing that springs to mind is the directions of the elements, some change them, using their locality, others insist that is irrelevent as they are 'Kabbalistic directions' and some further say Kabbalistic directions are based on location (Israel) in the first place ... so you can see, already it has become a muddle and leads to more advanced concepts.
Its often a good idea to stick with one system and focus on that until a basic groundwork is established, get to know and understand the principles FIRST then, eventually, you may adapt it to your own needs, or experiment with variation.
"And if any of you, do practice the LBRP these days? or have done in the past?, and if so, what are your thoughts, feels and experiences from it. If not, why not …. etc etc "
That is a paper in itself. There is quiet a bit here on it, I know I have posted numerous times about it. Have you tried the search function? I dont want to write it all out again.... I might if you were a sincere and dedicated practitioner, but if you are just curious and seeking verbal or written explanation .... search function.
Just a comment on vibrating the names; I agree with C G that no deep voice is needed (Crowley's was a thin horrible wail ) just get it vibrating, feel it spread through your body and project it out, imagine a bell ring vibrating (which is a good analogy - see Crowley's chapter on the use of the magick bell *) , 'everything' should start vibrating in sympathy.
The word vibration has two parts, I agree with CG about letting each letter resonate but there is also the 'changing vibration', the effect of one vibration changing into another ... I percieve it as a 'analogue signal' and not a 'digital' one, that is not EEEE .. (stop).... AHHHH ..... OHHH But EEEYYAAHHHHOOOOO ( I A O is a good practice ... or A U M ) ) . I also think each letter should be drawn out equally (some seem to prefer A U MMMMMMMMMMMMMMMMM IAOOOOOOOOOOOOOOOOOO )
* " .... During certain meditation-practices the Student hears a bell resound in the depths of his being. It is not subjective, for it is sometimes heard by other people. Some Magicians are able to call the attention of those with whom they wish to communicate at a distance by its means, or, so it is said.
" ... The sound of this Bell is indescribably commanding, solemn, and majestic. Without even the minutest jar, its single notes tinkle fainter and fainter into silence. At the sound of this Bell the Universe ceases for an indivisible moment of time, and attends to the Will of the Magician. ... The manifested shall repeat itself again and again, always a clear thin note, always a simplicity of music, yet ever less and less disturbing the infinite silence until the end. "