I have $8k for investment (warchest $32k no touch). FSMone RSP or SCB for lowest fees and lump-sum or DCA? Saw scb free brokerage fees rebate promo. Any advice?

22yo Will like to know which is more desirable. Lump-sum $4k into IWDA, $2k into FTEC, $2k into QQQ using SCB, or DCA $500 monthly into FTEC and VT ($250 each) using FSMone for 16months? Will hold and not sell since this $8k set aside I don't need it. Am leaning towards DCA because of the volatility and uncertainty whether market will go up or down in this covid economy. I really appreciate all advice so do give suggestions if u don't agree with the above etfs and what u prefer. Thank you!!