Ive been quoted these systems
18 x LG NeOn 2 350W Panels and Fronius Primo 5.0-1-I 5kw Inverter $7,890.00
18 x Jinko 370W JKM370M-66H Panels and Huawei SUN2000-5KTL-L1 5KW 1PH 2MPPT $4,190.00
18 x Jinko 370W JKM370M-66H Panels and Fronius Primo 5.0-1-I 5kw Inverter $4,390.00
18 x Trina 370W TSM-370DD08M.08(II) and Growatt 5000TL - X Dual MPPT 5kw $3,656.00
They are all priced at about what I’d expect given the products, except maybe the LG one looks a touch high.
My personal preference would probably be the Jinko and Fronius for the prices given. However, if you can get than LG price down a bit, that would definitely be the best quality system.