This is one time when size matters...
Reel sizes are like hook sizes...pretty much standard. So your 4500 Diawa is pretty much the same as a 4500 Shimano.
Note: 4500 is same as 45. 5000 is same as 50. etc. Some parts of the world add two zeros. I guess it might be a marketing thing...A 5000 model sounds better than a 50 model !!
I think you are looking to small. Your 8 foot rod is great for lakes and rivers. But you want to LBG, so you want to go off the rocks and maybe beach. 10 foot is minimum and even then you will struggle. 12 foot is good and 13 or 14 foot is even better. 12 foot will get the job done, yet is still good for a quick spin in the lake on the way home. If you are throwing lures, distance is important. An 8 foot rod just wont do it.
Reel size... If you want to stick with a thread line (ie egg beater) a 50 is absolutely rock bottom minimum. It is not about grunt or power, it's about line capacity. A 3kg banito hitting a lure at "hunting" speed can easy snap 30 pound line. So you need line capacity to let the fish run. A 20kg or even a 10 kg yellow fin tuna can strip 200 meters or more off your reel in seconds...and yes, yellow fin and other tuna, marlin, mackerel, tailor, kingies etc are all on the hit list if you throw lures out there. And yes, I did say tailor, they can grow to 90kg and they are more aggressive than sharks...so I am told.
I have spent many years LBG fishing so I know exactly what is needed. Most of my LBG is ballooning and live baiting. But I do throw lures out there as well. My all time favourite for off the rocks lure tossing, is my 10 foot Ugly Stik with my Silstar GXB80...Not the best combo, but a s***load of fun.
Now, a suggestion you might not have thought of....An Alvey.
As far as I know, Charles Alvey still holds the world record for the longest cast ever. He is of course not with us anymore...as in passed away, like dead. If throwing lures off the rocks in LBG distance is the key !! The longest casting reel in the world is not only in your budget, but it is Australian made ;). This might also be a surprise to most, the Alvey has a very fast retrieval speed...In fact, I do not know of any geared reel, thread line or overhead, that can bring a lure in faster than an Alvey. There is a learning curve if you wanted to use an Alvey. But plenty of good demos on Youtube. Also, to get the best out of an Alvey, the rod needs to have a large stripper guide, which will narrow your choices a bit.
