setting up small business 401k in US if want to retire in Canada

[dobiedoc]

Question: I am a small business owner in the US and setting up my US 401K plan (I have 5 employees) and retirement planning. If we want to return to Canada after retirement age (timeline 15-20 years), are there advantages to having the funds in after-tax funds (husband could open a solo 401K/Mega backdoor Roth as he is a 1099 independent contractor) or tax deferred (regular 401K) plans for Canada/US tax treatment? I can do a backdoor Roth. Also does anyone have experience in whether ETFs or index funds are better to make up the choices in the portfolio (ie would I want to choose VTSAX, VTIAX, VBTLX or VTI, VXUS, BND)? Any experience in dealing with Vanguard/ishare/Fidelity/Schwab for ease of transborder transition? I know that working with a financial advisor 3 years ahead of my move back is wise, but I need to decide this big question for 401K plan set-up this year. I am in my late 40s and dual citizen. Husband is 50 and Cdn Citizen with GC. Unsure (50:50%) of whether we will repatriate back to Canada or stay in the States (dependent on my teenager daughter and where she lands-who knows?).

[dobiedoc]

Anyone?? Even if you could share your mistakes or things to avoid I would be so appreciative for your experience.