Triangle Variation /Delayed Stonewall

Hi all,
what is the best reply, if black plays 1. d5 2. c6 3. e6 4. f5 or 2. e6 3. c6 4. f5? Meanwhile normaly White normaly has played 1. d4 2. Sf3 3. e3 4. Ld3 (or 4. c4) and is going into a regular Dutch Stonewall (no Dangerfield Attack or Lg5 variation).

Thanks!
Sleepy